Thermal detector, thermal detection device, and electronic instrument

Abstract

A thermal detector has a thermal detection element in which a physical characteristic changes based on temperature, a light-absorbing member configured and arranged to collect heat and transmit collected heat to the thermal detection element, a support member mounting the thermal detection element on a first side with a second surface facing a cavity, and a support part supporting a portion of the support member. The light-absorbing member is a plate shaped member at least partially contacting a top part of the thermal detection element and having a portion overhanging to an outside from the top part of the thermal detection element in plan view.

What is claimed is: 
     
       1. A thermal detector comprising:
 a thermal detection element that changes physical characteristics according to temperature; 
 a light-absorbing member configured and arranged to collect heat and to transmit collected heat to the thermal detection element, the light-absorbing member being a plate shaped member at least partially contacting a top part of the thermal detection element and having a portion overhanging to an outside from the top part of the thermal detection element in plan view; 
 a support member including a first side and a second side opposite from the first side with the thermal detection element being mounted on the first side and the second side facing a cavity, and the thermal detection element being disposed between the support member and the light-absorbing member; and 
 a support part supporting and linking to a portion of the second side of the support member. 
 
     
     
       2. The thermal detector according to  claim 1 , wherein
 the thermal detection element is a pyroelectric detection element including a capacitor that changes an amount of polarization according to temperature, the capacitor including a first electrode, a second electrode, and a pyroelectric body disposed between the first electrode and the second electrode, and 
 the light-absorbing member has a surface area greater than a surface area of the capacitor of the pyroelectric detection element in plan view. 
 
     
     
       3. The thermal detector according to  claim 2 , wherein
 the pyroelectric detection element further includes
 a protective layer protecting an outer surface of the capacitor with the protective layer forming a contact hole passing through to the second electrode, 
 a plug filling the contact hole and having both electrical conduction properties and heat transfer properties, and 
 a wiring layer formed in a prescribed pattern on the protective layer and the plug, and 
 
 the light-absorbing member is linked to the second electrode via the plug and the wiring layer. 
 
     
     
       4. The thermal detector according to  claim 3 , wherein
 the pyroelectric detection element further includes
 a first reducing gas barrier layer disposed between the protective layer and an outer surface of the capacitor, and 
 a second reducing gas barrier layer covering the protective layer and the wiring layer. 
 
 
     
     
       5. A thermal detection device comprising:
 a plurality of the thermal detectors according to  claim 3  arranged in two dimensions along two intersecting axes. 
 
     
     
       6. The thermal detector according to  claim 3 , wherein
 the plug is in contact with a region of the second electrode constituting 50% or more of a surface area of the second electrode in plan view. 
 
     
     
       7. A thermal detection device comprising:
 a plurality of the thermal detectors according to  claim 6  arranged in two dimensions along two intersecting axes. 
 
     
     
       8. The thermal detector according to  claim 2 , wherein
 the pyroelectric detection element further includes
 a protective layer covering a side surface of the capacitor and a portion of a top part of the capacitor with the protective layer forming a contact hole in a position corresponding to the top part of the capacitor, 
 a plug filling the contact hole and having electrical conduction properties, and 
 a wiring layer formed in a prescribed pattern on the protective layer and the plug, and 
 
 the light-absorbing member covers, in plan view, the capacitor in a region other than a wiring contact region in which the plug and the wiring layer covering the plug are disposed. 
 
     
     
       9. The thermal detector according to  claim 8 , wherein
 the wiring contact region is disposed in a position away from a center position of the second electrode in plan view. 
 
     
     
       10. The thermal detector according to  claim 8 , wherein
 the pyroelectric detection element further includes
 a first reducing gas barrier layer disposed between the protective layer and an outer surface of the capacitor, 
 a second reducing gas barrier layer covering the protective layer and the wiring layer, and 
 a third reducing gas barrier layer disposed between the light-absorbing member and a region of a top surface of the second electrode not covered by the protective layer. 
 
 
     
     
       11. A thermal detection device comprising:
 a plurality of the thermal detectors according to  claim 2  arranged in two dimensions along two intersecting axes. 
 
     
     
       12. The thermal detector according to  claim 1 , wherein
 the light-absorbing member includes
 a plate-shaped support layer covering the top part of the thermal detection element and overhanging to the outside from the top part of the thermal detection element in plan view, and 
 a heat collection layer formed on the support layer. 
 
 
     
     
       13. A thermal detection device comprising:
 a plurality of the thermal detectors according to  claim 12  arranged in two dimensions along two intersecting axes. 
 
     
     
       14. The thermal detector according to  claim 1 , wherein
 the thermal detection element is a pyroelectric detection element including a capacitor that changes an amount of polarization according to temperature, the capacitor including a first electrode, a second electrode, and a pyroelectric body disposed between the first electrode and the second electrode, and 
 the light-absorbing member includes
 a plate-shaped support layer covering a top part of the second electrode and overhanging to an outside from the top part of the second electrode with the support layer having a surface area greater than a surface area of the capacitor in plan view, and 
 a heat collection layer formed on the support layer. 
 
 
     
     
       15. The thermal detector according to  claim 14 , wherein
 the support layer is made of electrically conductive material, and 
 the pyroelectric detection element includes
 a protective layer covering a side surface of the capacitor, and 
 a wiring layer formed in a prescribed pattern on the protective layer, the wiring layer being electrically connected to the second electrode via the support layer. 
 
 
     
     
       16. A thermal detection device comprising:
 a plurality of the thermal detectors according to  claim 15  arranged in two dimensions along two intersecting axes. 
 
     
     
       17. A thermal detection device comprising:
 a plurality of the thermal detectors according to  claim 14  arranged in two dimensions along two intersecting axes. 
 
     
     
       18. A thermal detection device comprising:
 a plurality of the thermal detectors according to  claim 1  arranged in two dimensions along two intersecting axes. 
 
     
     
       19. An electronic instrument comprising:
 the thermal detection device according to  claim 18 . 
 
     
     
       20. An electronic instrument comprising:
 the thermal detector according to  claim 1 .